1. Field of the Invention
The present invention relates to a liquid ejection recording head adapted to eject a liquid such as ink thereby performing recording.
2. Description of the Related Art
In a known structure of a liquid ejection recording head, the liquid ejection recording head includes an electric wiring substrate having a lead electrode connected to a recording element substrate and also having a lead electrode (referred to as a dummy lead) that is not connected to the recording element substrate. The recording element substrate has an electrode pad for use in testing an electric function of the recording element substrate and also has an electrode pad necessary for realizing a function of the liquid ejection recording head. In general, the dummy lead is disposed at a location corresponding to a test electrode pad.
As disclosed, for example, in Japanese Patent Laid-Open No. 2004-255866, the purpose of the dummy lead is to prevent a sealing agent from sinking during a process of sealing electrodes thereby to obtain a stable shape of the electrode sealing agent. The dummy lead is not a part essential to electrical functions or functions of the liquid ejection recording head, but the dummy lead is provided on the electric wiring substrate in order to achieve the stable shape of the electrode sealing agent as described above.
In one of known configurations of such a liquid ejection recording head, the liquid ejection recording head is integrated with an ink tank for storing ink therein. To produce such a type of liquid ejection recording head, a recording element is connected to an electric wiring substrate, and the electric wiring substrate and the recording element are bonded via an adhesive to a supporting member made of a resin. In this process, a wire connection part between the electric wiring substrate and the recording element substrate, electrodes, and the peripheral part of the recording element substrate are sealed with a sealing agent. The adhesive and the sealing agent are cured by applying heat thereto.